1540-35-8Relevant articles and documents
5,7-Bis(2′-arylethenyl)-6H-1,4-diazepine-2,3-dicarbonitriles: Synthesis, and experimental and theoretical evaluation of the effects of substituents at 5,6,7-positions on the molecular configuration and spectral properties
Tarakanov, Pavel A.,Simakov, Anton O.,Dzuban, Alexander V.,Shestov, Vladimir I.,Tarakanova, Ekaterina N.,Pushkarev, Victor E.,Tomilova, Larisa G.
, p. 1138 - 1146 (2016)
A series of novel 5,7-bis(2′-arylethenyl)-6H-1,4-diazepine-2,3-dicarbonitriles was synthesized through sequential aldol condensation reactions of 1,3-diketones with diaminomaleonitrile, and the resulting 5,7-dimethyl-6H-1,4-diazepines were condensed with aromatic aldehydes. The substituents' effects on the spectral properties and conformational states of the molecules in solution were studied using 2D NMR techniques and DFT calculations. Specific intramolecular steric interactions in derivatives substituted at the C6 position were discovered and investigated in detail. Differential scanning calorimetry and thermogravimetric analyses revealed the strong dependence of the thermal stability of the newly prepared diazepinodicarbonitriles on the nature of the substituents. This offers new insight into the structure-property relationships of arylethenyl-substituted diazepine derivatives.
Synthesis of substituted 3-cyano-2-pyridones: Part IV - Influence of 3-alkyl-2,4-pentanedione and N-alkyl cyanoacetamide structure on the enzyme catalyzed synthesis of substituted 3-cyano-2-pyridones
Mijin, Du?an ?.,Mili?, Branislav D.,Mi?i?-Vukovi?, Milica M.
, p. 993 - 1003 (2007/10/03)
Lipase from Candida rugosa has been used to study the influence of 3-alkyl-2,4-pentanedione and N-alkyl cyanoacetamide structure on the enzyme catalyzed reaction of pyridone ring formation in water at 40°C. Starting with 1,3-diketones and cyanoacetamides and for comparison, the expected corresponding substituted 3-cyano-2-pyridones have been synthesized by chemical methods. Bulkier substitueras lower the initial reaction rate of the enzyme catalyzed reactions and consequently the yield of the corresponding pyridones. N-alkyl cyanoacetamides are more reactive in comparison to the corresponding 3-alkyl-2,4-pentanediones with respect to the obtained yields of the corresponding substituted 3-cyano-2-pyridones.
Substituent Effects on the CC Bond Strength, 16. - Thermal Stability and Enthalpies of Formation of β-Dicarbonyl Compounds. - Stabilisation Enthalpies of α,α'-Diketoalkyl Radicals
Noelke, Margot,Verevkin, Sergej P.,Beckhaus, Hans-Dieter,Ruechardt, Christoph
, p. 41 - 52 (2007/10/02)
The geminal interactions of the two carbonyl groups in seven β-diketones of the type 8-9 and 11-13 were estimated from their enthalpies of formation, which were deduced from their heats of combustion and enthalpies of vaporization.The radical stabilisation enthalpies RSE of the α,α'-diketoalkyl radicals 9-13 were obtained from the enthalpies of activation ΔH(excit.) of thermal CC bond cleavage of eight model compounds of the type 9-13 by their comparison with ΔH(excit.) of comparable hydrocarbons of similar strain.For non-cyclic α,α'-diacylalkyl radicals and six-membered cyclic ones RSE = 54.8 +/- 1.3 kJ mol-1 was determined, which indicates an additive stabilisation by two carbonyl groups. - Key Words: Enthalpies of formation/ Geminal substituents, energetic interaction of/ Bond cleavage, C-C, kinetics of/ Radicals, stability of/ Increments, thermochemical/ Bond strength, substituent effects on
